It is well known to monitor persons, such as infants, using a so-called baby monitor or baby alarm. Such known devices typically consist of a baby unit having a microphone and a parent unit having a speaker, thus allowing parents to hear the noises the baby makes when they are not in the baby's immediate vicinity. The baby unit and the parent unit may be connected by wire, but typically have a point-to-point radio connection, in some products allowing two-way traffic so the parents can remotely talk to the baby. Some more advanced models even have a camera in the baby unit, allowing the parents to remotely watch the baby. An example of such an advanced model is the Philips Avent® Digital Video Baby Monitor (www.usa.philips.com/c-p/SCD603_10_avent-digital-video-baby-monitor/overview).
The advent of smartphones has brought baby-sitting apps. These software programs or apps allow the parent unit to be constituted by a smartphone. This is more convenient for the parents as they no longer have to carry a separate parent unit when visiting the neighbors. In addition, the distance between the parent unit and the baby unit is no longer limited to the range of the baby unit's radio transmitter (typically 150 m maximum). When using the internet to connect the baby unit and the parent unit, in principle any distance can be covered.
Using an internet connection instead of a radio connection, however, has the disadvantage that the connection is less reliable. As is well known, internet connections can be lost and Wi-Fi networks can go down without warning. In contrast to radio connections, the loss of an internet connection generally is not detected when using a baby monitor. Most baby monitors only transmit sound when the baby unit detects a sound, so most of the time the parent unit or smartphone will receive no data from the baby unit. The absence of received data is therefore no indication of the malfunctioning of the IP connection. It will be clear that this is undesirable.
United States Patent Application US 2013/0182107 discloses an activity monitoring system which may include a smartphone in and a wireless network camera. The smartphone may periodically communicate, via the internet, with a remote server. The server may alert a user if the communication with the smartphone fails. However, the connection between the wireless network camera and the smartphone is not checked.